93: Digital Ray Amputation

Published on 18/04/2015 by admin

Filed under Surgery

Last modified 22/04/2025

Print this page

rate 1 star rate 2 star rate 3 star rate 4 star rate 5 star
Your rating: none, Average: 0 (0 votes)

This article have been viewed 2813 times

Procedure 93 Digital Ray Amputation

Pao-Yuan Lin, Sandeep J. Sebastin, Kevin C. Chung

imageSee Video 69: Digital Ray Amputation

Indications

image Traumatic amputation close to the metacarpophalangeal (MCP) joint that leaves a gap in the hand

image Elective procedure in patients with a functionally impaired digit

image Treatment of infection, failure of replantation, vascular disorder, or tumor

Examination/Imaging

Clinical Examination

image In patients undergoing ray amputation for a painful stump, the point of maximal tenderness due to a neuroma (if any) should be identified preoperatively and marked. Figure 93-1 shows a patient with a painful stump.

image

FIGURE 93-1

Imaging

image Radiographs of the hand (Fig. 93-2).

image

FIGURE 93-2

Surgical Anatomy

image The deep transverse metacarpal ligament connects the volar plates of the MCP joints of the index, long, ring, and small fingers. The flexor tendons, neurovascular bundles, and lumbrical tendon pass palmar to the deep transverse MCP ligament, whereas the interosseous tendon lies dorsal to it (Fig. 93-3).

image

FIGURE 93-3

Positioning

image The procedure is performed under tourniquet control. It can be done under regional or general anesthesia. The patient is positioned supine with the affected extremity on a hand table.

Exposures

image A racket-shaped incision is marked around the base of the finger. On the dorsum, this incision extends over the proximal metacarpal in a longitudinal fashion (Fig. 93-4A). On the palmar aspect, it is designed as a V (Fig. 93-4B).

image

FIGURE 93-4

Pearls

The incision is made on the finger that is going to be amputated and not into the web. This allows a good repair of the web space after the ray amputation.

Procedure

Step 1

image The extensor digitorum communis (EDC) tendon is identified on the dorsum, divided at mid-metacarpal shaft, and raised as a distally based tendon (Fig. 93-5). The juncturae to the adjacent fingers are also divided.

image

FIGURE 93-5

Step 1 Pearls

The extensor indicis proprius (EIP) or the extensor digiti quinti minimi (EDQM) tendons will have to be divided at the same level as the EDC when a ray amputation of the index or small finger is being carried out.

Step 2

image The periosteum is incised longitudinally on the dorsum of the metacarpal, and the interosseous muscle on both sides of the metacarpal shaft is separated from the metacarpal, along with the periosteum, to about 1 cm distal to the respective carpometacarpal (CMC) joint to preserve the insertion wrist flexor or extensor tendons.

Step 2 Pitfalls

Care must be taken not to elevate the extensor carpi radialis longus (ECRL), extensor carpi radialis brevis (ECRB), or extensor carpi ulnaris (ECU) from the base of the index, long, and small metacarpals, respectively.

Step 3

image A transverse osteotomy of the metacarpal shaft is done using a saw about 1 cm distal to the CMC joint by preserving the insertions of the ECRL, ECRB, or ECU.

Step 3 Pearls

The osteotomy for the index finger is done more distally at the level of the neck of the metacarpal in an oblique fashion; this allows the new web space to have a more natural slope (Fig. 93-6). In addition, it preserves the transverse width of the palm and the origins of the first dorsal interosseous and the adductor pollicis muscle.

The osteotomy of the small finger metacarpal is also done like the index finger (oblique and distally).

image

FIGURE 93-6

Step 4

image The common and proper digital arteries and nerves are identified through the palmar incision.

image The A1 pulley and flexor tendons are also identified.

Step 5

image The proper digital nerves to the finger undergoing ray amputation are divided distal to the origin from the common digital nerve using a blade and allowed to retract into the proximal soft tissues (Fig. 93-7).

image

FIGURE 93-7

Step 5 Pitfalls

One must ensure that the nerves are correctly identified before dividing them.

The proximal end of the nerve must be handled minimally to prevent any subsequent symptomatic neuroma formation.

One must ensure that the nerve has retracted proximally and that there is good soft tissue overlying it.

Step 6

image The proper digital arteries are also ligated and divided distal to their origin from the common digital artery.

Step 6 Pitfalls

There are interconnecting vessels between the deep and superficial arch at the level of the metacarpal neck. They must be identified and divided. Otherwise they will result in troublesome bleeding, once the tourniquet is released.

Step 7

image The A1 pulley is opened, and the flexor digitorum superficialis and profundus tendons are divided.

Step 8

image The deep transverse intermetacarpal ligament is identified at the neck of the metacarpal and divided close to the metacarpal shaft.

Step 8 Pearls

It is important to divide the deep transverse intermetacarpal ligament close to the shaft so that enough ligament is available to do a strong repair subsequently.

Step 9

image The finger is now freed from any other soft tissue holding it and excised (Fig. 93-8).

image

FIGURE 93-8

Step 10

image Two or three loops of 2-0 braided sutures (Ethibond or similar) are placed into the ends of the intermetacarpal ligament (Fig. 93-9).

image The gap between the heads of the adjoining metacarpals is reduced manually and maintained using two or three transverse Kirschner wires (Fig. 93-10).

image The intermetacarpal ligament sutures are then tied.

image

FIGURE 93-9

image

FIGURE 93-10

Step 10 Pearls

When setting tension, one must ensure that there is no scissoring of the digits. This is done by passively flexing and extending the wrist (tenodesis) to see whether the fingers fall into a good cascade (Fig. 93-11).

image

FIGURE 93-11

Step 11

image The tourniquet is deflated, and hemostasis is performed.

image The subcutaneous layer of wound is repaired by absorbable suture, and the skin is closed with 3-0 nylon (Fig. 93-12).

image

FIGURE 93-12

Postoperative Care and Expected Outcomes

image A short-arm plaster of Paris volar splint is applied by immobilizing the wrist and the fingers.

image The wound is inspected, sutures are removed, and a thermoplastic splint applied 10 days after the operation.

image Gentle active finger motion exercises are initiated, with splinting protection for another 4 to 6 weeks.

image The K-wires are removed 4 to 6 weeks later, and the patient is allowed unrestricted motion.

image Figure 93-13 shows the postoperative appearance at 5 months’ follow-up.

image Most authors have reported 25% to 30% loss of grip strength following ray amputation. The average time off from work is about 13 weeks.

image

FIGURE 93-13

Evidence

Melikyan EY, Beg MSA, Woodbridge S, et al. The functional results of ray amputation. Hand Surg. 2003;8:47-51.

A retrospective analysis of 20 patients who underwent ray amputation was done an average of 32 months after the procedure. The authors used the DASH questionnaire, physical examination, and functional testing. They found that patients had lost an average of 27% of their grip strength and 22% of their three-point pinch strength. The DASH function score was 29.2. Nine patients returned to their previous occupations. The authors concluded that the disability caused by ray amputation was acceptable to most patients. (Level IV evidence)

Peimer CA, Wheeler DR, Barrett A, et al. Hand function following single ray amputation. J Hand Surg [Am]. 1999;24:1245-1248.

The authors assessed and contrasted the results of primary and secondary reconstructive ray amputation. They demonstrated that primary ray resection is associated with less total cost with respect to the injury itself and subsequent disability. Most patients returned to their preinjury occupation and were subjectively satisfied with the appearance and function of the hand. A very curious finding was the significant differences in grip strength, key pinch, oppositional pinch, and rate of manipulation test results in those patients who had unsettled litigation and compensation issues. These differences could not be explained on a physical or anatomical basis, implicating secondary gain issues. (Level IV evidence)

Related posts:

81: Ulnar Shortening Osteotomy 61: Trapeziometacarpal Ligament Reconstruction 21: Steindler Flexorplasty 50: Open Reduction and Internal Fixation of Phalangeal Shaft Comminuted Fractures 21: Steindler Flexorplasty 37: Duplicated Thumb Reconstruction